OR-94-06-4 -- Comparison of Numerical Predictions of Horizontal Nonisothermal Jet in a Room with Three Turbulence Models - k-epsilon EVM, ASM, and DSM PDF

A three-dimensional nonisothermal jet in a room is analysed numerically by the standard k-epsilon eddy viscosity model (EVM) and two second-moment closure models - the algebraic stress model (ASM) (Hossain and Rodi 1982) and the differential stress model (DSM) (Launder et al. 1975). Numerical results given by these turbulence models are compared with experimental results, and the prediction errors existing in the results are examined, thus clarifying the relative structural differences between the k-epsilon EVM and the second-moment closure models. Since the second-moment closure models clearly manifest the turbulence structures of the flow-field, they are more accurate than the k-epsilon EVM. A small difference between the DSM and the ASM - one based on an inappropriate approximation of the convection and diffusion terms in the Reynolds stress transport equations in the ASM - is also observed.

KEYWORDS: comparing, horizontal, air jets, rooms, turbulent flow, models, calculating, comparing, experiment, accuracy, air flow, air movement, heat flow, temperature distribution, air diffusion, convection